Tamper-evident closures of various types and designs are well known devices that are used on containers to provide an indication to the consumer that the container has been open. Such closures generally include a cap portion and a security ring portion connected to the lower edge of the cap portion by a failure line. Typically the ring portion of the closure comprises a plurality of tabs extending upwardly and inwardly so as to abut against an annular flange that is part of the neck of the container after the closure has been screwed in sealing position. As soon as someone tries to remove the closure from the container, the failure line breaks and causes the ring portion to separate from the cap portion and thus give a visual indication that the container has been open. Closures of this type are described, by way of examples in U.S. Pat. Nos.
4,478,343 PA1 4,550,844 PA1 4,595,110 PA1 4,801,030 PA1 4,807,771 PA1 4,978,017 PA1 5,007,545
As can be easily understood, it is desirable for the tamper-evident closures to be easily manufacturable at low cost and be versatile for use with a large variety of containers.
It is also desirable to obtain a tamper-evident closure where the connection between the cap portion and the ring portion is more resilient upon screwing so as to facilitate installation of the closure onto the container. Another advantage sought in the conception of tamper-evident closures is the obtention of a closure which allows the failure line to break easily when someone tries to unscrew the closure.